By Laurence Hammack, The Roanoke Times, www.roanoke.com 24 May 2011
Invenergy is asking the FAA to raise the minimum altitude over its proposed windmills.
Rather than reduce the height of four windmills deemed to be a hazard to aviation from their proposed perch atop Poor Mountain, the developer of the wind energy project is asking that the airplanes fly a little higher.
In a plan submitted to the Federal Aviation Administration last week, Invenergy sought special status for the four turbines, which would entail raising by 200 feet the minimum altitude for passing aircraft.
Invenergy, a Chicago-based wind energy company, wants to build 18 turbines as part of a wind farm in Roanoke County.
The FAA ruled in March that 14 of the proposed structures would not endanger aviation. The remaining four, the agency found, posed problems because they would stand higher than 4,200 feet above sea level – affecting the minimum altitude for planes approaching Roanoke Regional Airport.
At the time, an FAA spokesman said Invenergy could relocate the turbines or shorten them to bring them into compliance.
Instead, the company is asking that the four turbines – which would sit together at the bend of a U-shaped formation that follows two ridgelines along the Poor Mountain summit – be given an “isolated prominent obstacle status.”
Such a status would raise the minimum vectoring altitude for airplanes in the area from 5,200 feet to 5,400 feet, or at least 1,000 feet above the highest obstacle.
FAA rules allow for such a designation, said Don Giecek, business development manager for Invenergy.
“It’s not an approach that Invenergy is putting on the table and starting anew,” Giecek said.
All 18 of the proposed turbines would stand 443 feet from the ground to the tip of their blades. The four too-tall turbines are to be built on higher ground than the others, putting them slightly above the 4,200-foot elevation preferred by the FAA.
Raising the minimum altitude for passing aircraft – even by just 200 feet – to accommodate the windmills would make flying more difficult, said Matt Broughton, president of a local aviation club.
“Two hundred feet can make a difference between icing and not icing. It can make a difference between being in the clouds and being in the clear,” Broughton said. “It’s dangerous. So why do it?”
Giecek said it could take several months for the FAA to rule on the company’s latest proposal. An FAA spokesman was not available for comment Monday.
Meanwhile, Roanoke County is considering an ordinance that would regulate the turbines, which some residents fear will be an eyesore and source of noise and flickering shadows. Supporters see the turbines as a valuable form of renewable energy at a time when the country needs to reduce its carbon footprint.
Invenergy is committed to working with both the FAA and county officials to address concerns, Giecek said.
“Our goal remains to work with the community and responsibly develop a model renewable energy project,” he said.
URL to article: https://www.wind-watch.org/news/2011/05/24/energy-company-seeks-to-gain-altitude-for-windmills/